This invention relates to food, and more particularly to a matrix which may be used to form a suitable food capable of being used alone or in mixture with other foods.
In the food art to make a particular type of food, it is usually necessary to assemble individual components and mix them in a particular order at an appropriate time to achieve the desired results. Keeping each of these individual components creates many problems. For example, each component may require separate storage. In some cases, the components must be stored separately because they cannot be mixed prior to use and retain stability. This problem exists even though there are a number of common components in a variety of foods. If some way can be found to stabilize a mixture of some common components in a food, then the storage capabilities of these common components are simplified. If these components can be mixed, it is feasible to store the mixture and not use separate storage facilities for each component. In addition to the storage advantages of using such common components in a wide variety of foods to form the mixture, it is also possible to achieve a composition or matrix which may greatly simplify processing and forming of foods in other arts. To form a composition or matrix having these capabilities is an advantage to the food arts in general. Additionally the composition can be particularly useful in the pet food art.
Within the class of foods known as pet foods there are three basic subdivisions--dry pet food, semi-moist pet food, and moist pet food. The moisture is determined by considering both the water present in the final product and the water combined with the various components that make up the final product. In general, the dry pet food--due to its low moisture content which is usually less than about 15 percent--tends to exhibit the greatest microbiological stability and requires no special handling or packaging upon distribution.
At the opposite end of the spectrum is the moist pet food having a moisture content in excess of about 50 percent. Due to the high moisture content of the moist pet food, microbiological stability is a major problem. This problem in a moist pet food is overcome only by heat sterilizing the moist pet food and packaging the moist pet food in a hermetically sealed container. Even with the heat sterilization and hermetically sealed package, refrigeration is required after the package of moist pet food is opened to preserve the leftover pet food for even a short time.
Semi-moist pet food has a moisture content generally ranging from about 15 percent to about 50 percent. Since semi-moist pet foods are higher in moisture content than dry and lower in moisture than canned, special techniques are required to render it microbiologically stable. This moisture content in combination with special techniques may produce a microbiologically stable food which does not require refrigeration. At the same time, the higher moisture content of the semi-moist pet food provides an increased palatability when compared to the dry pet food. The semi-moist pet food is generally rendered microbiologically stable by using appropriate combination of appropriate solutes. In this fashion, shelf stability without refrigeration is achieved while providing a food having increased palatability relative to dry pet food.
When considering palatability, the moist pet foods are the most palatable and the dry pet foods are least palatable. The semi-moist pet foods fall somewhere in between the moist and dry pet foods as to palatability. Thus dry pet food has both advantages and disadvantages.
One of the reasons for the lack of consumer and animal acceptance of a dry pet food is its poor palatability in relation to a semi-moist or moist pet food. A second reason for the lack of consumer and animal acceptance for a dry pet food is the hard, brittle characteristic thereof. This hard, brittle characteristic detracts from the overall appearance and texture of the product. This hard, brittle characteristic also distinguishes the dry pet food from the semi-moist or moist pet food. One advantage, however, that a hard abrasive textured pet food has, is that it contributes to teeth cleaning of the pet.
One possible solution for improving the palatability of the dry pet food is adding water thereto. While such addition of water provides a somewhat increased palatability, the product is more susceptible to microbiological deterioration. Thus it cannot be left out at room temperature for the pet to eat for more than a few hours before it has to be discarded. Also the water softens and moistens the hard, brittle pieces and almost all of the teeth cleaning attributes are lost. This solution, therefore, is not suitable because the desired teeth cleaning attributes are sacrificed to achieve palatability. The problems are not offsetting. Thus, this solution does not provide a desirable result.
A second way to increase palatability is to mix foods with semi-moist or canned pet foods. However, such mixtures usually result in rapid textural changes in the respective components. Moisture transfers from the semi-moist or canned component to the dry component, causing its inherent hard texture to become soft. Similarly, loss of moisture from the semi-moist component caused their inherent, soft, elastic meat-like textures to become hard. This creates two problems. The conventional dry dog food which is now soft has its teeth cleaning attributes reduced or eliminated. The semi-moist product, which is now dry and brittle, but not hard and abrasive, results in a product having reduced palatability. Also, with either a semi-moist or a canned product, the moisture that transfers to the dry product will render the dry product microbiologically unstable. Thus, this mixture of dry and semi-moist or dry and canned product requires immediate consumption by the pet in order to avoid the textural instability and the onset of the microbiological spoilage that inherently occurs.
Some attempts to manufacture a dry pet food that is soft and palatable are known. Some progress is evident in the field of manufacturing a soft dry pet food alone. However, the products thus formed do not have the desirable teeth cleaning characteristics inherent in a dry pet food of the hard type, and the palatability has been suspect. So, while there are two different types of dry pet food, hard dry pet food and soft dry pet food,--there is no dry pet food on the market combining the attributes of the hard pet food with its teeth cleaning benefit and the soft dry pet food with its palatability and textural benefits.
A further problem in the manufacture and usage of soft, dry pet foods is that despite all attempts to the contrary they become hard upon storage. This hardness developing upon storage destroys the effect desired. It is desired to maintain the softness over a substantial period of time to retain the inherent values of having the softness while at the same time maintaining the storage stability. A number of attempts to overcome the problem of foods becoming brittle during storage is known in the art. Some attempts to form a soft dry pet food involve the use of lecithin as a fat transporting and cohesive agent to achieve the desired softness. Other attempts to make a soft dry pet food are known which have used expensive proteinaceous adhesives or other protein sources which are difficult to obtain in combination with starch and plasticizing agents to form a soft dry pet food. Because of the availability or high cost of these proteinaceous adhesives, and other ingredients, these products are not commercially feasible. Also the softness of these products is retained for only a short period of time when the product is stored at room temperature.
Thus it is clearly desirable to provide a means for making a foodstuff that retains its softness for long periods of time, if possible, and can be mixed with a hard foodstuff without losing its integrity, and is economical to produce. It is especially desirable if this means may be applied to the making of soft dry pet food. It is furthermore desirable to produce a matrix or base that can be used as a starting point for many types of soft products. The soft dry pet food thus produced is especially advantageous if it provides for excellent palatability in a soft product. If this soft product can be mixed with a hard dry pet food as known in the art, the advantages of palatability for the soft piece and teeth cleaning attributes of the hard piece may be achieved in the same food.